Induction-furnace.



E A, F. HIORTH. INDUCTION FURNAUE. APPLIOATION FILED Nov. 20,1906.

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KARL .ALBERT FREDRIK I-IIOELTH, 0F CHRISTIANIA, N(IRI/WAY.

Specification of Letters Patent.

,raten-ted Apr. 1.2, 191e.

Application filed November 20, '1906. Serial No. 344:,305.

To all whom it may concer-nf.'

Be it known that I, KARL ALBERT FRED- nin Hion'rH, a subject of the King of Norway, residing at Christiania, Norway, have invented certain newland useful Improvements in Induction-Furnaces; and I'do hereby declare the following to be a full,

clear, and exact description of the invention, such as will enable others skilled in the means whereby the continuity of the annulus vof molten metallic material m the annular hearth as partially or wholly broken, in combination with means,whereby the current may be led through the slag at the point where the annulus is broken.

I shall now describe the invention, reference being had to the drawings, showing different modes of carrying out the process.

Figure l lis a perspective view showing a furnace adapted for carrying out my invention. Fig.V 2 is a sectional view illustrating another mode of carrying out my invention; Fig. 3 is a plan corresponding with Fig. 2. Fig. 4 shows another modification. Fig. 5 is a perspective view of a furnace similar to the one shown in Fig. l showing a modification. Fig. (5 is a sectional view illustrating another modification. l

In the drawing Fig. 1 illustrates myinven` tion applied to a double induction furnace as described in another application Serial Number 344,303, filed by me simultaneously with the present application.

A, A are induction furnaces having a common magnet ring or core B.

C is a bridge or a Wall built up in the annular channel of one of the furnaces.

D, D are electrodes 'and E a connecting piece 0f conducting material between the electrodes, which latter are arranged to dip only in the slag. Instead of the connecting ieee E a conductor F ma i be -used havin@ 7 E:

a part which forms a secondary coil around the core B, as shown in Fig. 5.

The bridge C should be so arranged as to allow of being taken out, when the furnace is to be used as an induction furnace. The current will then cause an energetic heating of the metallic charge while the slag will be less heated. When the furnace is used with the bridge inserted and the electrode D in operation, the slag around the electrode terminals will be highly heated and so called energetic slags are obtained. As shown in Fig. G bridge C may be provided with a narrow aperture c, which allows of a passage of the metallic charge.

I may carry out the two electrodes in the form of a double'or horseshoe-formed electrode B, which may be mounted on a crane G, so that it is easily lifted. In some cases I suspend this horseshoe-electrode by a link g which is pivotally connected to the crane, so that it may be given an oscillatory movement, whereby the charge is given a wave motion, and new portions of the slag brought within the reacn of the electrodes.

I may use several bridges as here explained in the furnace and combine them with electrodes.

'I'he invention may also be carried out without electrodes as indicated in Fig. 2.

In this inst ance the bridge C is only carried up to the bottom of the slaffand`the slag in this case forms the lead1ng connection between the separated parts of the molten metallic charge. As mentioned above I may provide such bridges at. several points and I may as indicated 'in Fig. 3 make the annular hearth wider, where the bridge is inserted in order to obtain a greater cross sectional area of molten slag and thereby a greater conducting capacity. I may also as shown in Fig. 4- provide.the .feeding chute right above the bridge, whereby the material fed down into the hearth will be eX- posed to the greatest heat and a rapid smelting` down of the material is thereby secured.

l. In an induction furnace, the combination with the annular hearth, of one or more bridges to decrease the sectional area of the annulus of the molten metallic-charge, and an electrode dipping into the slag only on each side of the bridge and a current conducting device between thc electrodes to cause an electric current to pass from the :metaiic chang on one sio of the bridge to the me'tli'c charge on the other side of the bridge @through .die slag and electrodes.

2. En an ,induction furnace, the combinaion with 'she annum? hearth, of one or more bridges eoioase the sectional area, of the annulus of lbhe moiten metalliclcharge, an eiect'oe dipping into the slg only on each Side of 'tho bridge, :pourront conducting device between the electrodes and a secondqiiy Icoil of a transformer included in said oon- KARL ALBERT FREDRIK HIORTH.

Witnesses:

THS. BERG, JOLE VAALER. 

